Pompe's disease (also referred to as glycogen-storage disease type II or acid-maltase deficiency) is a rare autosomal recessive disorder that results in an accumulation of glycogen in the lysosome due to a deficiency of acid alpha glucosidase (GAA). The build-up of glycogen causes progressive muscle weakness (myopathy) throughout the body and affects various body tissues, including the heart, skeletal muscles, live, and nervous system.
Pompe's disease is broadly classified into infantile and late onset forms. In the infantile-onset form, infants typically present during early infancy (4-8 months of age) with weakness and floppiness, and are unable to hold up their heads and cannot do other motor tasks common for their age, such as rolling over. Without treatment, infants with Pompe's disease usually die before 12 months of age due to heart failure and respiratory weakness. See, United Pompe Foundation. Late onset forms (including juvenile and adult forms), have a later onset and progress more slowly than the infantile form. Recombinant human GAA (Myozyme® or Lumizyme®) is used to treat Pompe's disease. However, Myozyme® or Lumizyme® are both very expensive, with costs well over $300,000 per year. As such, there is a need for improved treatments for Pompe's disease.